Latching valves are known. An example is shown in commonly-assigned United States Patent Publication No. 2011/0315503. Latching valves may be used to hold pressure in a transmission clutch or brake when an engine is stopped. This pressure helps speed re-engagement of the clutch or brake when the engine is restarted. A transmission strategy may include a desire to determine the operating state of the latching valve to determine whether the latching state has been successfully achieved.